EPA Section 609 MVAC Technician Certification PreparationApproved ProgramsMVAC Requirements
Refrigerant identification

Refrigerants, Fittings & Labels

R-12, R-134a, R-1234yf, R-744, SNAP acceptability, labels, fittings, and contamination prevention.

Identify before connecting

Use vehicle labels, unique fittings, service information, and approved identification procedures.

R-12 is ozone-depleting

CFC-12 was used in older MVACs and has significant ozone-depletion and climate effects.

R-134a and R-1234yf are not interchangeable

They use different equipment and fittings; mixing can contaminate cylinders, equipment, and vehicles.

R-744 has a narrow venting exception

Carbon dioxide is exempt from the Section 608 venting prohibition, but Section 609 certification and equipment requirements still apply to paid MVAC service.

Common mistakes

  • Charging by cylinder color alone
  • Treating substitutes as drop-in replacements
  • Using universal adapters
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